學生姓名:
郭百濼
指導教授:
黃登福
學期:
110下
摘 要:
CTXs are natural marine lipophilic toxins which may cause ciguatera poisoning (CP)in humans. This illness is the most prevalent foodborne disease caused by non-bacterialorganisms reported globally. CTXs and other toxic metabolites are produced by a group of microalgae principally of the genus Gambierdiscus and Fukuyoa. These compounds reach high trophic levels throughout the food chain. Initially, only large carnivores seemed to pose a risk for toxin intake, however it is known that also smaller carnivorous, piscivorous, and herbivorous fish are able to cause this disease. This study reports the results of a field sampling campaign carried out in September 2018 in the Selvagens Islands. These islands are a marine protected area located at the southernmost point of the Portuguese maritime zone, have been associated with fish harboring ciguatoxins (CTX) and linked to ciguatera fish poisonings. Fifty-six fish specimens from different trophic levels were caught for CTX-like toxicity determination by cell-based assay (CBA) and toxin content analysis by liquid chromatography with tandem mass spectrometry
(LC-MS/MS). Notably, high toxicity levels were found in fish with an intermediate position in the food web, such as zebra seabream (Diplodus cervinus) and barred hogfish (Bodianus scrofa), reaching levels up to 0.75 µg/ kg CTX1B. The LC-MS/MS analysis confirmed that Caribbean ciguatoxin-1 (C-CTX1) was the main toxin, but discrepancies between CBA and LC-MS/MS in Diplodus cervinus and top predator species, such as the yellowmouth barracuda (Sphyraena viridis) and amberjacks (Seriola spp.). This study confirms that fish from coastal food webs of the Selvagens Islands represent a high risk of ciguatera. The Canary Islands are a CTX hotspot with an established official monitoring. Fish caught by recreational fishermen are not officially tested and the consumption of toxic viscera or flesh could lead to ciguatera poisoning (CP). The objectives of this study were to determine the presence of CTX-like toxicity in relevant species from this archipelago, compare CTX levels in liver and flesh and examine possible factors involved in their toxicity. One hundred and nine fish specimens were analyzed by CBA and C-CTX1 was detected by LC-MS/MS in all these species. Most of the liver displayed higher CTX levels than flesh and even individuals without detectable CTX in flesh exhibited hepatic toxicity. Black moray eels stand out for the large difference between CTX concentration in both tissues. None of the specimens with nontoxic liver showed toxicity in flesh.
專題討論20220323郭百濼_摘要.pdf